1. Field of the Invention
The present invention relates to an erroneous assembling preventing tool for a universal joint and a universal joint comprising the same.
2. Description of Related Arts
This type of universal joint comprises a yoke for connecting a shaft, and the yoke comprises a yoke main body. The yoke main body comprises a cylindrical section forming a slit axially extending, and first and second tabs that are opposed to each other with the slit sandwiched therebetween. A bolt inserted through a bolt insertion hole of the first tab is screwed into a screw hole of the second tab so that the shaft is fastened by the cylindrical section. As a result, the shaft is fixed to the yoke main body.
The shaft usually has a relief portion, which is in a circular arc shape in cross section, provided at a predetermined position in an axial direction of its outer periphery. The bolt is inserted through the relief portion. This causes the shaft to be regulated at a normal position of the axial direction by the bolt.
On the other hand, there is a case where the amount of insertion of the shaft into the cylindrical section is insufficient so that the shaft does not reach the normal position (in a so-called incompletely fitted state). In this case, a front end of the bolt interferes with the shaft, so that the bolt cannot be inserted into the screw hole of the second tab. This prevents such erroneous assembling that the shaft, which is not at the normal position, is assembled in the yoke main body (see Japanese Unexamined Patent Publication No. 2001-280361, for example).
In such an incompletely fitted state that a front end of the shaft does not reach the position of the bolt, however, the shaft may, in some cases, allow the insertion of the bolt. In this case, the erroneous assembling may occur.
An object of the present invention is to provide an erroneous assembling preventing tool for a universal joint, which can reliably prevent erroneous assembling of a shaft, and a universal joint comprising the same.